Wireless Ceiling Alarm / Remote Control Product# HS4900D   $39.95  Free Shipping This alarm  mounts to the ceiling where it can detect motion within 360 degree circle up to 20 feet away If motion is detected the unit will emit a 110dB alarm or 90dB chime.  When the alarm is activated by motion after the entry delay the alarm will sound for 1 minute if no further motion is detected.  This unit includes an remote controls that operate up to 25' away from the alarm.  It has a 30-45 second exit delay and a 10 second entry delay.  It operates on 3 "C" batteries which are not included. The unit can also be powered by a 7.5-15 volt adapter that is not included.